600+hp with a XR Drive??
 

Alittle help....... A buddy of mine is building a 600+hp. out of a 540 blk. He had a 500HP Bulldog 525HP before teamed up with a Bravo1 XR drive. Will the XR hold up with the new HP?
What r the XR drives rated at? Been reading and seeing that anything 600 or more can run the #6 dry sump drives better with that HP.
Any thoughts guys............ :rolleyes:

PS. the boat is a 1996 253 Checkmate Convincer

Re: 600+hp with a XR Drive??
 

I would say the XR would be OK for that size of boat. The Number 6 would be overkill for a checkmate that size, if he wanted to go up from an XR, I would say go with a Max Machine Works drive, or above that a Konrad

Re: 600+hp with a XR Drive??
 

If i he treats it right it will live, an XR can hold 800HP with the right man at the throttles, or you can blow it up with 300HP if you try. The 6 drive would be way to much for that boat, although the spec sheet calls for it for 600HP plus applications you don't ussualy start seeing them till atleast 800HP and it's not uncommon to see bravos behind 1000 HP (an ill concieved idea but finacially understandable) Konrada are another great alternantive but they require a transmission and that probably isn't an option in a small boat like that, unless he wants to go with race stly 3 man bolsters with no back seat.

Re: 600+hp with a XR Drive??
 

I ran a standard bravo 1 on my 272 baja w/around 650hp for over 100 hours before breaking it. It was fine with a 26 pitch prop,added headers(25 hp or so) and went to a 28 pitch,broke almost immediately. Other than xr's wear out in 1/2-1/4 the time of a std bravo it should last seasons in such a small boat as long as idle isn't too high and it isn't revved to moon while airborn. I been running upgraded max xr'ssince,something seems to wear out or break every 50-100 hours but i'm running more hp and torque than your buddy and i don't always let off when i'm catching a little air,Smitty
Something I believe in too is if your running a msd put a pill in that's 1 or 2 hundred rpm's higher than your max rpm's so if you catch air motor touches rev limiter instantly to limit shock when you re-enter water.Max makes best upgraded xr in my opinion too but your buddy will probably have failure from xr parts wearing before he does from too much power so its probably overkill.

Re: 600+hp with a XR Drive??
 

J bravo,i see your only 15 miles from me,pm me with some contact info,I'd like to meet you and your bud. I have a outdrive jack and alignment tool if you need to pull a drive that you can use at my shop with no charge too,Smitty

Re: 600+hp with a XR Drive??
 

I have a '99 259 Convincor. I am running 680 hp 660 torque through a stock XR upper and Imco Lower. I broke the vertical shaft in the lower a few weeks ago. However, I don't think I did all the damage. I got the drive used from a boat with big power. Treated correctly, you will be fine with the XR. BTW, the new Imco shafts dont have that senseless oil hole where it broke.

Re: 600+hp with a XR Drive??
 

yep..

Re: 600+hp with a XR Drive??
 

#6 is probably overkill for a 25-27' boat. Should be ok with an XR.

Re: 600+hp with a XR Drive??
 

Your experience is discouraging us from repowering our Checkmate. It appears more power hands you more problems.

Re: 600+hp with a XR Drive??
 

Yep. You just keep breaking more expensive parts.

Are we haveing fun yet? :D

Re: 600+hp with a XR Drive??
 

Not really. He found out the motor was built half ass! Stock connecting rods dont hold up after 200hrs. on 525hp. Other than that happening this yr. the past have been good running! :D

Re: 600+hp with a XR Drive??
 

I have an XR upper and a IMCO lower with 800 hp on a 26 ft cat going on 3 years no problems ... knock on wood... I wouldnt say im all that easy on it either.

Re: 600+hp with a XR Drive??
 

When you guys are breaking drives, what actually is breaking? Shafts? Gears? Bearings? Don't know?

Re: 600+hp with a XR Drive??
 

RJBBC,

I wouldn't let my experience be any kind of deterant. As I said, I got the drive used. I am 100% positive that the shaft had a crack in it from when I got the drive. I am confident the drive will last for a while now.

Re: 600+hp with a XR Drive??
 

ECeptor,

What I have seen in the past couple of years is dependant on the model of drive and where it's weak points lie.
The older standard Bravo's used to push the floor of the gear out. The new X gears with thicker floors stopped that problem.
I see 25-28' boats with blowers eat teeth off the pinion gears or driven gears, thats when I recommend the step up to an XR.. If you break teeth, move up. If your not breaking teeth then an uprade to the X gears is a good move. The next week link will be the tower in the standard Bravo. When ever a standard Bravo breaks teeth, I have seen the tower egg shape. I have been installing my own steel towers to prevent that but when the old tower is milled off there can be cracks down below.
On the XR's on heavy boats (11k - 16K) The weak link seems to be the vertical shaft in the lower, I replace that with the Imco piece that was upgraded about a year ago. I have not had the opportunity to do that for one of the heavy boats yet. But I have seen plenty of the stock XR shafts break.
In the lighter boats with heavy power the XR gears will wear out early. Typical use seems to be 200-250 hrs. Extreme use, 60-70hrs. I have one drive I built on a 25 H2x with 966hp that runs over a 100mph and the guy drag races it constantly with a 32" prop. It is very fast on acceleration. He had some motor problems and while it was being looked at, I did an inspection of the drive. The upper gears were worn out, but every thing else seems to be ok.. I will be working on that today and will see if there is anything else that took it's toll while being run so hard.
A lot has to do with setup. Just proper setup on a 50' boat I was servicing increased XR life from 20hrs to 80hrs. But I was never allowed to build one like I did for the 25' H2x.. A lot has to do with the way you drive your boat and what kind of water you run in...
I have rambled enough.. I hope this gives you some insight.. I would be happy to answer any questions and share my experiences..

Dick